A wiring substrate is provided with an insulating resin film; and first and second conductive films provided on the back side and top side of the insulating resin film, respectively. The wiring substrate includes a via formed to fill a recess provided in the insulating resin film and electrically connecting the top side and back side of the insulating resin film. The via includes a first metal film formed to cover the side wall of the recess, an oxide film formed to cover the first meal film, and a second metal film formed on the metal oxide film.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A wiring substrate comprising: a substrate; and wiring that fills a recess in the substrate, wherein the wiring comprises a first metal film that covers the side wall of the recess, a metal oxide film that covers the first metal film, and a second metal film on the metal oxide film.
2. The wiring substrate according to claim 1 , wherein the first metal film and the second metal film are copper.
3. The wiring substrate according to claim 1 , wherein the metal oxide film is an oxidized form of the first metal film.
4. The wiring substrate according to claim 2 , wherein the metal oxide film is an oxidized form of the first metal film.
5. The wiring substrate according to claim 1 , wherein the substrate is an insulating resin film.
6. The wiring substrate according to claim 2 , wherein the substrate is an insulating resin film.
7. The wiring substrate according to claim 3 , wherein the substrate is an insulating resin film.
8. The wiring substrate according to claim 4 , wherein the substrate is an insulating resin film.
9. The wiring substrate of claim 2 wherein the metal oxide film has a thickness equal to or less than 10 nm.
10. The wiring substrate of claim 2 wherein the metal oxide film has a thickness equal to or less than 1 nm.
11. The wiring substrate of claim 10 wherein the metal oxide film has a thickness equal to or greater than 0.1 nm.
12. A method of fabricating a wiring substrate comprising the steps of: forming a recess in a substrate; forming a first metal film so as to cover the side wall of the recess; forming a metal oxide film on the first metal film by oxidizing the surface of the first metal film; and forming a second metal film on the metal oxide film.
13. The method of fabricating a wiring substrate according to claim 12 , wherein the first metal film and the second metal film are formed of copper.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 26, 2005
February 17, 2009
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